The invention relates to a method for feedback control of a controlled variable.
In a feedback control process, a control loop, formed from a feedback control system that has an influence on the behavior of the feedback control and from a controlled system that effects feedback, is used to compare the actual value of a controlled variable (the physical quantity to be controlled) with a command variable corresponding to the setpoint value of the controlled variable. And a deviation between setpoint value and actual value of the controlled value is minimized with the help of a manipulated variable that acts on the controlled variable.
In a second or higher order control loop, the actual value of the controlled variable can overshoot the setpoint value as a result of a step change in the command variable. The transient behavior of the control loop has been found to be disadvantageous because it is dependent on temperature influences and degradation phenomena. This dependence can lead to a slow settling phase or to an unstable working point in which the controlled variable is excited to oscillation even by slight disturbances.